Sometimes in certain hands I wonder if there are certain things that happen where a specific player can hurt your equity without trying to. Perhaps you have an opponent who calls often when you raise. This gives another opponent a good opportunity to squeeze with a lot of hands. The original person who calls you can sometimes be a trapper. His excessive calling can hurt your equity because you won't be able to continue with as many hands. It also hurts him because he is calling with weaker hands that will probably fold to the 3-bet. This is just an example where mutual ****age can occur. You are forced to open a tighter range and thus make less money.

Another spot. Would be where you 3-bet a MP player and a SB or BB player overcalls with a weaker range giving the original opener a call that would otherwise be a fold. I use to 3-bet some mid suited connectors as a standard, but I've noticed that sometimes it is unprofitable due to overcalling. At a table full of great opposition I would consider it a good play. With cold call happy blinds, it is hitting the muck.

There can also be "teamwork" (not really teamwork since it isn't intentional). Pretend that you limp in after an UTG limper and a field of other players limp in as well. The button player raises big. UTG folds. Your hand should be a fold if everyone after you folds, but if you call, it will cause a chain reaction of the other players calling making your hand profitable to call. So your EV is dependent on the unspoken agreement that you all call to lower the buttons equity. In the end someone is getting screwed over in equity, but you still hurt the Button player nevertheless.

This can really hurt in tournaments. Say you hold TT in late position. Someone in EP pushes all-in. Another player goes all-in as well. You end up folding. The first player has 55. The second player has 92s. The second player has done mutual hurt to both your hand and his hand. He bluffed with a hand that didn't make sense because it hurt his own EV, but it also hurt yours. I find that when you play in a tournament with a GTOish strategy in mind it can actually hurt you, because you end up folding too much because the bad player mutually hurts yours and his own equity.

A general GTOish strategy assumes your opponents are going to play well. Could this suggest that there is a spectrum of GTO startegies and in theory it isn't possible to play a static strategy without first adapting to the opponent's strategy?

Tough question to answer and I'm not even close to qualified enough to guess.

The most obvious example of another player affecting your EV is in a 3 way pot with a dry side pot and the opponent bets making you fold a hand that would have beat the all in player but wins vs that opponent. But your examples are also good.

Nobody knows yet if a "GTO solution" for multiway NLH poker exists and the closest thing we're gonna get to it is likely an approximation done by really strong computers/software.

Poker Snowie has some interesting ranges for spots in multiway pots. Its heads up game is pretty strong imo, but I wonder how it would fair in a tournament setting with multiple players that don't play the same strategy. I theorize that its equity would be stolen by bad play from certain players and transferred to another/other player(s) of adequate ability.

At a table full of solid players, I imagine it would beat everybody.

If I recall correctly, I vaguely remember Tom Dwan saying that there wasn't a GTO solution to poker. Which he may have meant no single static solution for a table with multiple opponents.

I think it's fairly well known that a fish in a multiway pot can kill the EV of playing the GTO strat, due to factors that you mentioned, like calling and giving someone else the right odds to overcall and suck out, or raising with a hand that shouldn't be raised and making you fold the best hand.

It happens to me a lot in spots where someone c-bets or donks with a hand that shouldn't be leading out, and someone calls with a hand that should always fold... and I fold the best hand because the c-bet and the flat call by the middle player look so strong, but then it turns out everyone's clueless.

Amen, McFly, I've folded the better hand in that position multiple times. I'm still trying to get into the head of those players to understand their thinking. In the wise words of my wife, "They aren't thinking so you'll never understand them."

As to Godson's post, I agree with your thinking. It's my opinion at this point that Poker Snowie teaches you how to play against other Poker Snowie trained players. Against ITO players (Idiot Theory Optimal) I'm not yet convinced that it transfers will.

Also, it's a small sample size so I'm hesitant to even mention it, but Snowie says I'm playing at a world class level...yet I'm down significantly in cash game scenarios. I'm still sticking with Snowie for now, but I'm having trouble recognizing value in it's teachings thus far.

Some concepts that you may want to look up include Morton's theorem and implicit collusion.

I feel like my best skill is playing in multi-way pots, so I generally prefer to never get it heads up unless the pot is big. I like playing where the fish in the game is the aggressive guy who keeps trying to iso and gets tilted because he can never get it heads up. I've adopted the strategy of limping a lot more so he can't 3bet me.